Fix creation of objects with acronym names (e.g. "O&J") (#17633)

Fixes https://github.com/twentyhq/twenty/issues/17544

**Problem**
When users create custom objects with short acronym names like "O&J",
the system generates an object name oJ. When creating relation fields,
the morph field name was built using string concatenation:
const morphFieldName = `target${capitalize("oJ")}`; // → "targetOJ"
This produced "targetOJ", which failed validation because the camelCase
check performed in `validateFlatFieldMetadataName` (camelCase(name) ===
name) returns "targetOj" for "targetOJ". The issue comes from
consecutive camelCase() operations.

**Solution**
Actually, the `camelCase(name) === name` check is questionnable. 
What we want to check is that a name is in camelCase format, not that it
corresponds to the camelCase version of a given string, while that's we
are doing here. lodash does not provide camelCase validator, only
camelCase convertor, so we used it as a way to validate the format of
the name.
We may feel like `camelCase(name) === name` checks whether a name is
camel-cased, but in addition to that it is also checking for a camel
case "idempotency" we don't necessarily have and do not need: for
instance if an object's name is "iOS" (which could be inferred from a
label "I O S"), it won't pass the check: camelCase("iOS") is "ios" and
"ios" !== "iOS".

The existing check with
`STARTS_WITH_LOWER_CASE_AND_CONTAINS_ONLY_CAPS_AND_LOWER_LETTERS_AND_NUMBER_STRING_REGEX`
acts as a camel case validator, so we don't need that camelCase() check.

packages/twenty-server/src/engine/metadata-modules/flat-object-metadata/validators/utils/validate-flat-object-metadata-name.util.ts

@@ -1,5 +1,4 @@
 import { msg } from '@lingui/core/macro';
-import camelCase from 'lodash.camelcase';
 import { RESERVED_METADATA_NAME_KEYWORDS } from 'twenty-shared/metadata';
 
 import { type FlatObjectMetadataValidationError } from 'src/engine/metadata-modules/flat-object-metadata/types/flat-object-metadata-validation-error.type';
@@ -41,16 +40,6 @@ export const validateFlatObjectMetadataNames = ({
       });
     }
 
-    // CamelCase check
-    if (name !== camelCase(name)) {
-      errors.push({
-        code: ObjectMetadataExceptionCode.INVALID_OBJECT_INPUT,
-        message: `Name should be in camelCase`,
-        userFriendlyMessage: msg`Name should be in camelCase`,
-        value: name,
-      });
-    }
-
     // Format check
     if (
       !name.match(